With our new o-line coach, I think there is reason to believe we will see a lot of improvement on last year's offense, even with the same players (although I'm hoping for a couple changes). Warhop was truly terrible and I've long believed he was a main culprit in the line's poor play. This site attempted to put metrics to all the o-line coaches' values:
Optimum Scouting - Offensive Line Coaches
Seattle saw a significant increase in o-line play switching from Cable (-78.2) to Solari (-32.8) despite Solari still ranking poorly relative to the rest of the league. According to this site, we are trading out Warhop at -103.8(!!!) for Kugler at -17.5. Tag Donovan for a year and see if Kugler can do anything with him. If not, move on. Benenoch can still gtfo though.